Snitzerland is a simple mare to decipher.

If she works well on the training track, she is competitive on the racetrack.

Happily for trainer Gerald Ryan the four-year-old produced one of her finest gallops on Tuesday morning which augurs well for her attempt at back-to-back wins in the Challenge Stakes at Randwick.

"When she works well, she races good," Ryan said.

"She's only had three fair-dinkum gallops this time in - the trial at Rosehill, the race and Tuesday morning when she worked as good as she has worked."

Snitzerland meets a high-class field led by outstanding Queensland sprinter Buffering.

The pair has met twice, most recently in the Moir Stakes last spring when Buffering finished second to Samaready while Snitzerland disappointed and was later diagnosed with a respiratory problem.

Their only other clash was in the 2012 Patinack Farm Classic when neither horse fired.

Buoyed by Snitzerland's breakthrough Group One win in the Black Caviar Lightning Stakes last month, Ryan is looking forward to meeting Buffering with a fit and happy horse.

"We've met him two times and he's beaten us in the Moir when we weren't at our best, and (then) in the Patinack she was a spring filly at the end of her campaign," he said.

"She hasn't met him before when she's been at her best."

The two are vying for favouritism in the Challenge Stakes with Snitzerland at $2.70 narrowly holding sway over Buffering at $3.